Many different types of communication systems have been developed and deployed, available for use to effectuate many different types of communication services. Many varied communication services are effectuated through use of different ones of the communication systems. Many of such communication services are practical necessities for many. And, ready access to communicate by way of an appropriate communication system is correspondingly necessary.
Improved, and additional types of, communication services shall likely become available as technological advancements warrant. When technological advancements are implemented in communication systems, the communication systems generally provide for more efficient communication of data, communication of data at higher communication rates, or communication of data in manners that better provide for successful communication of the data when communicated in adverse communication conditions. Many modern communication systems make use of digital communication techniques. Use of digital communication techniques provides various advantages that facilitate successful communication of data between communication stations of a communication system. Improved communication efficiencies are possible as communication redundancies are able to be removed from data prior to its communication. When the data is free of redundancies, the informational content of the data is able to be communicated with reduced bandwidth allocations or in reduced amounts of time. Additionally, the data that is to be communicated is more readily manipulated, such as by encoding, to increase the likelihood that the informational content of the data is successfully communicated upon communication channels susceptible to communication degradation.
A radio communication system is an exemplary type of communication system and is exemplary of communication systems that utilize digital communication techniques. In a radio communication system, data is communicated between communication stations by way of radio channels. Radio channels are defined upon a portion of the electromagnetic spectrum. When the radio communication system is regulated by regulatory bodies, the portion of the electromagnetic spectrum at which the radio channels are defined is allocated to the communication system. The communication stations operable in the radio communication system include at least a sending station and a receiving station. The sending station operates to convert data that is to be communicated into a form to permit its communication upon a radio communication channel. And, the receiving station operates to detect the data communicated upon the communication channel and to recover the informational content of the detected data.
Because channels are defined upon the electromagnetic spectrum in a radio communication system, various advantages are provided by radio communication systems over their wireline counterparts. Because need for a wireline connection to interconnect the communication stations of a radio communication system are obviated, communication of data is effectuable between communication stations positioned at locations between which wireline connections are unable easily to be formed. And, freed of the need to interconnect the communication stations by way of fixed, wireline connections, a radio communication system is amenable for implementation as a mobile communication system. In a mobile communication system, one or more of the communication stations between which data is communicated is provided mobility.
A cellular communication system is a mobile communication system. In a typical cellular communication system, a communication network is formed of a plurality of fixed-site base transceiver stations. The base transceiver stations are deployed at spaced-apart locations throughout an area that is to be encompassed by the communication system. Cells are defined that are the coverage areas associated with individual ones of the base transceiver stations. Radio communications are effectuated between a mobile node and a base transceiver station in whose cell that the mobile node is positioned. The conventional cellular communication systems provide for telephonic communications by a user of the mobile node. Through appropriate positioning of the base transceiver stations, a mobile node is always positioned within relatively close proximity to at least one of the base transceiver stations when the mobile node is positioned within the area encompassed by the cellular communication system. Because of the proximity, only relatively low-powered signals are required to be communicated by the mobile node to effectuate communications.
Generally, cellular communication systems are operated in conformity with an operating specification promulgated by a standard-setting body. Successive generations of operating specifications have been promulgated, and successive generations of cellular communication systems have been deployed in conformity with such operating specifications.
The networks of more than one generation of cellular communication systems might, for instance, be deployed over a common, or overlapping, area and be concurrently operable to provide for radio communications with mobile nodes operable in the respective communication systems. And, separate networks, operated by separate network operators, of the same generation might also be deployed over a common, or overlapping, area, also to be operable concurrently.
Generally, a service subscription is purchased by a user of the mobile node, and the mobile node is authorized to communicate by way of a communication system pursuant to the service subscription. The mobile node is typically associated with a home network portion. The home network portion is typically a network portion that is installed to encompass an area in which the user of the mobile node is most regularly positioned. However, because a mobile node is inherently mobile, the user of the mobile node, carrying the mobile node, might well roam beyond the coverage area of the home network portion associated with the mobile node. When the mobile node roams beyond its home network, the mobile node might be positioned at a location encompassed by another network portion, a visited network.
When the mobile node roams beyond its home network, the mobile node is selectably permitted to communicate by way of one, or more, of the visited networks in whose coverage area that the mobile node roams. Permission to communicate by way of a visited network is dependent, among other things, upon whether the mobile node and the visited network operate pursuant to compatible operating specifications. Also, agreements between operators of the visited and home networks are additionally determinative of whether the mobile node is permitted to communicate by way of a particular visited network.
Additionally, the mobile node might roam into an area encompassed by more than one network, each of which is available to the mobile node through which to communicate. A decision is made as to which of the available networks that the mobile node communicates. Conventional mechanisms are used in the decision-making process, typically including use of a defined set of preferred roaming partners. An operator of the home network associated with the mobile node maintains a list of the preferred networks. When the mobile node roams into a visited network, the mobile node communicates by way of the network listed on the preferred list.
While, historically, cellular communication systems have provided merely telephonic voice communications, increasingly, cellular communication systems provide for packet data communication services. Legacy networks, providing only voice or limited data services, are deployed in areas in which new-generation cellular communication systems that provide for increasingly-intensive data communication services are also deployed. A mobile node, capable of communicating pursuant to a new-generation, data communication service must communicate by way of a network that provides for such new-generation packet communication service for the effectuation of such service. Accordingly, when selection is to be made of with which visited network that a mobile node is to communicate, the capability of the visited network must be taken into account. A manner by which to facilitate such selection is needed.
It is in light of this background information related to communications in a radio communication system that the significant improvements of the present invention have evolved.